Polyvinyl acetal resin sheets containing diphenyl ether



Patented Dec. 6,

UNITED) STATES POLYVINYL AOETAL nEsm snns'rs CON-, mmme. nrrnnm n'rnsaHem- B. Smith and DonaId R. Swan, Rochester, N. Y., assignors to EastmanKodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing.Application December 3, 1937,

Serial No. 177,965

4 Claims. (Cl. 10622) This invention relates to plastic compositions,

and more particularly to compositions comprising a polyvinyl acetalresin and a conditioning agent. One object of this invention is toproduce 5 compositions of matter which may be made into permanentlytransparent, strong and flexible sheets or films of desired thinnesswhich are 'substantially waterproof, are unaffected by ordinaryphotographic fluids and possess the desired properties of a support forsensitive photographic coatings. Another object of our invention is toproduce compositions of matter which can be made into sheets suitablefor use in laminated, shatter-proof glass.

truded, molded or otherwise worked into relatively thick sheets andmassive plastics. A

further object is to produce compositions suitable for use in lacquers,artificial silk filaments,

wrapping tissues and the like. Other objectsmixture, such, for instance,as acetone, methanol,

acetone-methanol mixtures, ethylene chloridemethanol mixtures, etc.,about 300 to 500 or more parts of the solvent or solvent mixture.

being used per 100 parts of the resin. .From about 2 to 35 parts ofdiphenyl ether per 100 parts of resin may be employed, depending uponthe nature of the resin and the purpose for which the sheets are to beused. Suitable proportions of diphenyl ether for any resin and anypurpose 4 may readily be determined by experiment. For

the manufacture of sheets for photographic film base, from 2 to 25partsot diphenyl ether per 100 parts of resin are suitable. The resinsolution is cast as a sheet, solvent evaporated, an

stripped from casting surface;

' Diphenyl ether is not permanently compatible to the extent or 40 partsof diphenyl ether per 100 parts of certain of the polyvinyl acetalresins in sheets or films, a part of the plasticizer crystallizing outaftera few days. However, we have discovered that when from 12 to 28parts of di phenyl ether with from 28 to 12 parts or a lowerdialkyl-phthalate, such as diethyl phthalate or dibutyl phthaIate areused. with 100 parts of resin, an unusual and remarkable efiect is ob-Still another object .is to. l5 produce compositions which can berolled, ex-

; tained which we may call elastici zing That is to say, a sheet ofpolyvinyl acetal resin containing about 40 or more parts, per 100partsof polyvinyl acetal resin, of a mixtureof 30-70% diphenyl ether and-30% not lower dialkyl 5 phthalate possesses'the property which, in therubber industry, is known as nerve: namely, the property of stretchingto a considerable extent when tension is exerted upon it, and returningto its original dimensions when the tension 10 is released. Thisproperty renders such sheets, which we shall call "rubber-y sheets,particu-. larly useful in the manufacture of shatter-proof glass. Theuse oi 40 parts of I lower dialkyl phthalate alone with parts ofpolyvinyl acetal l5 resin does not produce a-rubbery sheet, except inthe case of dibutyi phthalate with the polyvinyl butyraldehyde acetalresins. In fact, when 50 parts of dibutyl. phthalate are used with 100parts of a polyvinyl acetaldehyde acetai resin, 20 the dibutyl phthalatetends to exude.

Sheets for use in laminated glass may be formed by casting, or may bemade without the use of volatile solvent by extrusion, for example inthe manner set forth in application Serial No. 25 147,934 of John S.Kimble and Ernest C. Blackard, filed June 12,1937. For example, 40 ormore parts of a mixture, of 30-70% diphenyl ether and 70-30% dibutylphthalate, and 100 parts of a polyvinyl acetal. resin may be mixed in asuit- 30 through. an annular die, and the tube so formed .slit' to form'a. sheet.

The polyvinyl acetal resins can be prepared by reacting polyvinylalcohol with an aldehyde in 40 the presence of an acetal condensationcatalyst, e. g. a mineral acid. These resins can also be prepared bysimultaneously de -esterifying a polyvinyl aliphatic ester and reactingthe deesterification product with .an aldehyde in the presence of a de-esteriiying catalyst and acetal condensation catalyst.- Mineral acidsare catalysts for both de-esterification and acetal formation. Among thepolyvinyl acetal resins with 50 which diphenyl ether is useful 'may bementioned,

as illustrative examples, the polyvinyl formaldehyde .acetal resins, thepolyvinyl acetaldehyde acetal resins, the polyvinyl-formaldehydeacetaldehydemixed acetalresins, the polyvinyl butyr- '55 and 7. Furtherexamples of the preparation of polyvinyl formaldehyde acetal resins areas follows:

lbs. of polyvinyl acetate, the viscosity of whose molar solution (86.08g. per liter) in benzene was 45 centipoises, was dissolved in 75 lbs. of70% acetic. acid. To this solution were added 56 grams of hydroxylaminehydrochloride,

for stabilizing the resin, 5.25 lbs of trioxymethylene, and 6.25 lbs of35% HCl. The reaction mixture was allowed to stand for 5 days at 40 C.,after which it was diluted with acetic acid. The

resin was precipitated by pouring into cold water,

washed, and dried. Analysis showed the resin to .have an-acetate groupcontent equivalent to 10.6%

by weight of polyvinyl acetate and a hydroxyl group content equivalentto 7.1% by weight of polyvinyl alcohol. The stabilization of polyvinylacetal resins by hydroxylamine is claimed in the application of JosephB. Hale, Serial. No. 149,916, filed June 23, 1937.

Examples of the preparation of polyvinyl acetaldehyde acetal resins maybe found in U. S. Patent 2,044,730,'Example 1; U. S. Patent 1,955,- 068,Example 2; U. S. Patent 2,036,092, Examples 4, 5 and 6; British Patent466,598, Examples 1, 2, 3, 4 and 7; British Patent 404,279, Examples1,2, 4, 5, 6, 7 and 8; U. S.Patent 1,990,399; and French Patent 808,578,Examples 1, 2 and 3.

An additional example of the preparation of a polyvinyl acetaldehydeacetal resin is as follows:

100 lbs. of polyvinyl acetate, the viscosity of whose molar solution inbenzene was 45 centipoises, was dissolved in 300 lbs. of 95% ethylalcohol. To this solution'were added 30 lbs. of paraldehyde and 25 lbs.of HCl. The reac-. tion mixture was allowed to stand 4 days at C afterwhich it was diluted with ethyl alcohol, and the resin precipitated bypouring into cold water, washedand dried; Analysis showed the resin tohave an acetate group content equiva lent to 2.1% by weight of polyvinylacetate and a hydroxyl group content equivalent to 12.9% by weight ofpolyvinyl alcohol.

Examples of the preparation of polyvinyl formaldehyde acetaldehyde mixedacetal resins may be found in British Patent 430,136, Examples 1, 2, 3,

4, 5 and 6; British Patent 445,565, Example 2;

British Patent 465,873, Examples 1, 2, 3, 4, 5 and 6; French Patent808,586, Examples 1, 2, 3, 4, 5, 6,,

12, 13, 1'4, 15, 16, 17, 18 and 19.

Additional examples of the preparation of polyvinyl formaldehydeacetaldehyde mixed acetal resins are given in the application of RalphH.-

Talbot, Serial No. 85,960, filed June 18, 1936, as

follows: jEzcample 1 100 parts (1.16 mol. calculated as monomeric vinylacetate) of a polyvinyl acetate centipoises), 100 parts of ethylalcohol, 180 parts of ethyl acetate, 34 parts (.77 mol. as monomericacetaldehyde) of paracetaldehyde and 5.8"parts (.196 mol. asmonomericformaldehyde) of paraformaldehyde wereplaced in an enamelledvessel and brought into solution bystirring. -Wh en solution was.complete, 10 parts of sulfuric acid (sp. g. 1.84) in 10 parts of waterwere added, and the mixture stirred. The mixture was maintained at atemperature of 40 C. for 144 hours. The contents of the vessel were thendiluted with about two and a half volumes of acetone, and the mixtureprecipitated into water. The precipitated resin was washed free fromimpurities by repeated changes of cold water, and dried. The resin, whenanalyzed, gave a hydroxyl group content equivalent to about 6.4 per centby weight of polyvinyl alcohol, an'acetate group content equivalent toabout 4.0 per cent by weight of polyvinyl acetate, a formaldehyde acetalgroup content equivalent to about 15.9 per cent by weight of polyvinylformaldehyde acetal and an' acetaldehyde acetal group content equivalentto about 73.9 per cent by weight of polyvinyl acetal I dehyde acetal.The polyvinyl acetal portion of the resin was therefore made up of about19.7 per cent by moles of polyvinyl formaldehyde acetal and about 80.3per cent by moles of polyvinyl acetaldehyde acetal. The resin wassoluble in acetone to an extent which permitted coating a film or sheetfrom the resin.

"Example 2 parts (.58 mol. as monomer) of polyvinyl acetate (45centipoises); 50 parts of ethyl alcohol, 90 parts of ethyl acetate, 17parts (.385

mol. as monomer) of paracetaldehyde, 2.9 parts (.098 mol. as monomer) ofparaformaldehyde, 5 parts of sulfuric acid and 5 parts of water weretreated as in Example 1 for 161 hours. The well washed and dried resingave upon analysis a hydroxyl group content equivalent to about 9.6%

by weight of polyvinyl alcohol, an acetate group content equivalent toabout 4.1% by weight of polyvinyl acetate, a formaldehyde acetal groupcontent equivalent to about 13.9.per cent by 3 weight of polyvinylformaldehyde acetal, and an acetaldehyde acetal group content equivalentto about 69.9 per cent of polyvinyl acetaldehydeacetal. The polyvinylacetal portion of the resin was therefore made up of about 18.5 per centby moles of polyvinyl formaldehyde acetal and 81.5

per cent by moles of polyvinyl acetaldehyde acetal.

The resin was soluble in acetone to an extent which permitted coating afilm or sheet from the resin.

Example 3 means of agitation, and the contents brought to a temperatureof about 70 C. bymeans of steam heating. 182.25 parts of sulfuric acid(sp. g. 1.85) dissolved in 51.5 parts of water were added,

and the whole was heated at about 70 C. for

about five hours, agitating throughout. At this point, 266.4 parts (6.05mol. as monomer) of paracetaldehyde were added and heating at about C.with agitation was continued for a further period of twenty hours. Thecontents of the reaction vessel ,were 'neutralized'with ammoniumhydroxide and diluted with water precipitating the resin as acake. Thecake was cut into small pieces and repeatedly washed with hot wateruntil the resin was free from solvents, salts and other impurities. Theresin, upon analysis,

showed a hydroxyl group content equivalent to amass:

about 10.1 per cent by weight of p lyvinyl alcohol, an acetate groupcontent equivalent to about 3.2 per cent by weight of polyvinyl acetate,the remainder of the weight of the resin being polyvinyl acetal. Thepolyvinyl acetal portion pf the resin was made up of about 80 percent bymoles of polyvinyl acetaldehyde acetal and about 20 per eent by moles ofpolyvinyl formaldehyde acetal. The resin was not quite soluble inacetone, but could be made to dissolve by admixing small amounts ofother solvents, such as alcohols,

with the acetone. a

Examples of the preparation of polyvinyl butyraldehydeacetal resins maybe found in U. S.

Patent 2,044,730, Examples 2, 5 and 6; 'British Patent 466,598, Example5; French Patent 813,303, Example 1; French Patent 813,514, Examples 1,2, 3 and 4; and British Patent-459,878, Examples 1, 2, 5, 6, 7, 8, 9and-10.

An example of the preparation of a polyvinyl butyraldehyde acetaldehydemixed acetal resin is given in French Patent 813,303, Example '2.

What we claim as our invention and desire to be secured by LettersPatent of the United States of diphenyl ether and 70-30% of a lowerdialkyl 10 phthalate. V 3. A transparent, rubbery sheet comprising 100parts of apolyvinyl formaldehyde acetal resin and, as an elasticizertherefor, at least '40 parts, approximately,

phthalate' 4. A transparent, rubbery sheet comprising 100 parts of apolyvinyl butyraldehyde acetal resin and,'as an elasticizer therefor,atleast parts, 20

approximately, of a mixture consisting of 30-70% of diphenyl ether and-30% of a lower dialkyl phthalate.

' I HENRY 3. SW.-

DONALDR. 25

of a mixture consisting of 30-70% 15 of diphenylether and 70-30%01 alower dialkyl

